Countries not on this list may still have production of olives, though LookLex has not been able to find any information on this.Ripe olives. Photo: Peter Firminger.Unripe olives, yet the source of the most common sort, the green olive.Olive trees. Photo: ride to dine.The outline of an olive farm. North of Sousse, Tunisia.

Subtropical, broad-leaved tree with a edible fruit from the family Oleaceae. It is generally the fruit which is just called 'olive'. The family contains about 900 species.For the region of this encyclopaedia, the growing of olives are in the countries bordering the Mediterranean Sea. The only country off this region, Iraq, has an illustratively low yield of 11,000 metric tons a year, compared with neighbouring Syria's 999,000.An olive tree takes 4 to 8 years to bear its first fruits, and doesn't reach full production before 15 to 20 years. Trees are usually planted in flat fields without competitive vegetation, and commonly 20 metres apart.The olive tree blooms in late spring, bearing small white flowers. There are two types of flowers. Either with male and female parts in one flower, or as just a male flower. Pollination is through wind.Fruits for oil are usually harvested when they are well-matured. Olives for eating are either harvested before being mature or just when they become mature. Olives are either picked by hand, or shaken off the tree and collected on the ground.Olives cannot be eaten directly from the tree. The fresh fruit has an extremely bitter taste, a result of a glucoside. The glucoside is neutralized by the treatment of the olives, usually by lye and salt applications. The colour of the olive is not a question of type, but of its ripeness. Unripe olives are green, ripe are dark blue, but become black from the treatment. There are other colours too, like purple, representing a near-ripe state.Olives are prepared for the consumer market in numerous ways. Some olives are sent directly to the market without much preparation, others have spices added. Often, the stone is removed, and the cavity is filled with garlic, sweet red pepper or other spicy vegetables.A large part of the olive production is pressed to make oil. The normal oil content of the olive fruit is around 20%. Olive oil is classified into 5 grades:

1. Virgin. This is the most valued oil, the product of the first pressing(s).
2. Pure. Partly virgin, partly refined oil (see 3.).
3. Refined. The residual pulp has water added, and pressed again. This produces an oil with more acid and odour. The acid, odour and colour is removed to make it edible.
4. High acid oil. This is not used for food, rather for lamps and other products.
5. Sulfide. Oil is extracted from the remaining raw materials, and refined repeatedly.

The history of the olive tree in the Middle East goes back to around 3000 BCE, while its spread to North Africa seems to have begun around year 0.